When to plant in Ripon, CA
USDA Zone 9bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Ripon, California — all computed from Ripon's nearest NOAA weather station.
With about 298 frost-free days, Ripon supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Ripon's nearest full-normals station sits about 18 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. Zone 9b is warm enough that Ripon can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Ripon is now 13 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
STOCKTON METRO AP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Ripon’s own odds, recorded at STOCKTON METRO AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 7 | Mar 10 | Feb 11 | Nov 4 | Nov 18 | Dec 2 |
| 32°F | Feb 28 | Feb 6 | Dec 31 | Nov 15 | Dec 1 | Dec 26 |
| 28°F | Feb 5 | Jan 10 | Dec 14 | Nov 29 | Dec 16 | Jan 14 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Ripon, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 21 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Ripon planting FAQ
When is the last spring frost in Ripon, CA?
Plan for the last spring frost in Ripon around February 6 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Ripon, CA?
Expect Ripon's first fall frost near December 1 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Ripon in?
Ripon is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Ripon?
There are roughly 298 frost-free days in Ripon (a long growing season), running from the average last frost around February 6 to the first fall frost near December 1.
When should I plant tomatoes in Ripon?
In Ripon, start tomato seeds indoors around December 12–December 26, then transplant seedlings outdoors around February 13 once the danger of frost has passed.
Never miss a window in Ripon
An email when it’s time to start seeds, transplant, and sow — timed to Ripon’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at STOCKTON METRO AP, 18 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Ripon, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00023237. Retrieved from https://blissgarden.com/california/ripon.